As a method to detect a wafer alignment mark by an exposure device, there is an image processing method. In the image processing method, an alignment mark over a wafer that exists in the field of view is monitored by an alignment scope mounted on the exposure device and is captured in the device, for example, by a charge-coupled device (CCD) camera as an alignment mark image. The captured alignment mark image is compared with a template figure that is set in the device to detect a specific alignment mark and a deviation amount of a wafer position is measured.
An alignment mark that is not a detection target could be erroneously detected if two or more alignment marks with substantially the same size exist in the field of view of the alignment scope when an alignment mark is detected. Therefore, an arrangement interval of alignment marks is determined based generally on a limitation according to a performance of an exposure device.
Related art of the present disclosure:    Patent document 1: Japanese Patent. No. 2947196    Patent document 2: Japanese Patent. No. 3572555
Alignment marks are often arranged over a scribe region of a semiconductor wafer. However, various process patterns with different sizes such as an alignment mark, an inspection mark, a monitor for process control are arranged over the scribe region of a general semiconductor wafer. Accordingly, arranging the desired number of image processing application marks over a scribe region with a certain interval has been difficult.
Moreover, there is a case in which a chip dedicated to a process pattern is provided to arrange an image processing application mark in the chip. However, arranging the desired number of image processing application marks with a certain interval requires a large number of chips dedicated to process patterns. As a result, the yield of product chips may be reduced.